Image reading apparatus and optical module using the same

Abstract

An image reading apparatus includes: a light irradiating means for irradiating light to a subject having images to be read; an image forming means for making the light from the subject incident on an image plane so as to form images as erected images; and a photoelectric conversion means for converting the incident light of the erected images into image signals, wherein the image forming means is constituted of a plurality of lens arrays that have a mutually identical shape and property and are sequentially disposed, sharing common light axes, between the subject and the photoelectric conversion means, and the respective lens arrays are formed by integral molding of a plurality of lenses, and an aperture provided with light passing holes with the light axes as the center is interposed at least between the plurality of lens arrays, and areas other than the light passing holes in the aperture form light shielding areas.

What is claimed is: 
     
       1. An image reading apparatus comprising:
 a light irradiating means for irradiating light to a subject having images to be read; 
 an image forming means for making the light from the subject incident on an image plane so as to form images as erected images; and 
 a photoelectric conversion means for converting the incident light of the erected images into image signals, 
 wherein the image forming means is constituted of a plurality of lens arrays that have a mutually identical shape and property and are sequentially disposed, sharing common light axes, between the subject and the photoelectric conversion means, and the respective lens arrays are formed by integral molding of a plurality of lenses, and an aperture provided with light passing holes with the light axes as the center is interposed at least between the plurality of lens arrays, and areas other than the light passing holes in the aperture form light shielding areas. 
 
     
     
       2. The image reading apparatus according to  claim 1 ,
 wherein the aperture is disposed, among the intermediate position, the light incidence side and the light reflection side of the plurality of lens arrays, at least at the intermediate position. 
 
     
     
       3. The image reading apparatus according to  claim 1 ,
 wherein the subject is disposed at a position closer to the image forming means than the focal plane of the image forming means formed at a side of the subject. 
 
     
     
       4. The image reading apparatus according to  claim 1 ,
 wherein the light irradiating means, the image forming means, the aperture and the photoelectric conversion means are unitized; the light irradiating means irradiates linear light to the subject while the unit moves along with respect to the subject, the linear light reflected from the subject passes through the light passing holes in the aperture, and the plurality of lens arrays form erected images of unity magnification on the image plane. 
 
     
     
       5. The image reading apparatus according to  claim 4 ,
 wherein the light irradiating means is constituted of a light emission element and a light guide body, the image forming means is constituted of a plurality of lens arrays which is formed by integrally molding a plurality of spherical lenses in a line shape by the same metal mold, the aperture is constituted of a light shielding film provided with a plurality of round light passing holes sharing the same center with the plurality of spherical lenses, and, furthermore, the photoelectric conversion means is constituted of a linear image sensor. 
 
     
     
       6. An optical module for image reading comprising:
 a light irradiating means for irradiating light to a subject having images to be read; 
 an image forming means for making the light from the subject incident on an image plane so as to form images as erected images; and 
 a photoelectric conversion means for converting the incident light of the erected images into image signals, 
 the light irradiating means, the image forming means and photoelectric conversion means being unitized, 
 wherein the image forming means is constituted of a plurality of lens arrays that have a mutually identical shape and property and are sequentially disposed, sharing common light axes, between the subject and the photoelectric conversion means, and the respective lens arrays are formed by integral molding of a plurality of lenses, 
 and an aperture provided with light passing holes with the light axes as the center is interposed at least between the plurality of lens arrays, and areas other than the light passing holes in the aperture form light shielding areas. 
 
     
     
       7. The optical module according to  claim 6 ,
 wherein the aperture is disposed, among the intermediate position, light incidence side and light reflection side of the plurality of lens arrays, at least at the intermediate position. 
 
     
     
       8. The optical module according to  claim 6 ,
 wherein the subject is disposed at a position closer to the image forming means than the focal plane of the image forming means formed at a side of the subject. 
 
     
     
       9. The optical module according to  claim 6 ,
 wherein the light irradiating means irradiates light to the subject in a line shape while the unit of the light irradiating means, the image forming means, the aperture and the photoelectric conversion means moves along with respect to the subject, the linear light reflected from the subject passes through the light passing holes in the aperture, and the plurality of lens arrays form erected images of unity magnification on the image plane. 
 
     
     
       10. The optical module according to  claim 9 ,
 wherein the light irradiating means is constituted of a light emission element and a light guide body, the image forming means is constituted of a plurality of lens arrays which is formed by integrally molding a plurality of spherical lenses in a line shape by the same metal mold, the aperture is constituted of a light shielding film provided with a plurality of round light passing holes sharing the same center with the plurality of spherical lenses, and, furthermore, the photoelectric conversion means is constituted of a linear image sensor. 
 
     
     
       11. An image reading apparatus comprising:
 a light irradiating unit configured to irradiate light to a subject having images to be read; 
 an image forming unit configured to make the light from the subject incident on an image plane so as to form images as erected images; and 
 a photoelectric conversion unit configured to convert the incident light of the erected images into image signals, 
 wherein the image forming unit is constituted of a plurality of lens arrays that have a mutually identical shape and property and are sequentially disposed, sharing common light axes, between the subject and the photoelectric conversion unit, and the respective lens arrays are formed by integral molding of a plurality of lenses, and an aperture provided with light passing holes with the light axes as the center is interposed at least between the plurality of lens arrays, and areas other than the light passing holes in the aperture form light shielding areas. 
 
     
     
       12. An optical module for image reading comprising:
 a light irradiating unit configured to irradiate light to a subject having images to be read; 
 an image forming unit configured to make the light from the subject incident on an image plane so as to form images as erected images; and 
 a photoelectric conversion unit configured to convert the incident light of the erected images into image signals, 
 the light irradiating unit, the image forming unit and photoelectric conversion unit being unitized, 
 wherein the image forming unit is constituted of a plurality of lens arrays that have a mutually identical shape and property and are sequentially disposed, sharing common light axes, between the subject and the photoelectric conversion unit, and the respective lens arrays are formed by integral molding of a plurality of lenses, 
 and an aperture provided with light passing holes with the light axes as the center is interposed at least between the plurality of lens arrays, and areas other than the light passing holes in the aperture form light shielding areas.